Such a bursty traffic multiplexing arrangement and such a method performed thereby are already known in the art, e.g. from the international application published under the Patent Cooperation Treaty (PCT) WO 95101029 entitled `Flow Control Method`. Therein, an arrangement called switch statistically multiplexes ATM (Asynchronous Transfer Mode) inputs into output flows which are provided at output ports thereof. The switch, as is seen in the figure on page 1 of the above cited document, includes an output queue to temporarily store the output flows. To avoid buffer congestion situations, i.e. situations wherein the output queue has insufficient storage capacity to store all data elements applied thereto, a receiving port in the network that the switch forms part of is enabled to transmit congestion indication messages to a source port in the network whenever congestion is approached. Upon receipt of such congestion indication messages, the source port reduces the permitted bandwidth or the transmit rate for transmission. As long as the source port does not receive such a congestion indication message, its transmit rate is increased in small increments.
If, in the arrangement, the multiplexing unit has insufficient throughput capacity to multiplex all input flows applied simultaneously to its inputs, these input flows are transformed before they reach the above output queue and output port. Consequently, information is lost. Obviously, this drawback of the known switch can be avoided by using a multiplexing unit with sufficient throughput capacity. In other words, no information is lost if the multiplexer throughput capacity is equal to or greater than the maximum aggregate input flow data rate. The use of such a multiplexer to multiplex input flows with bursty nature however implies that part of its capacity is left unused most of the time, and therefore this is no adequate solution.